Final answer:
Jean Piaget's theory states that during adolescence, children enter the formal operational stage of cognitive development, enabling them to think abstractly and logically about hypothetical situations.
Step-by-step explanation:
Jean Piaget believed that as children approached adolescence they began to engage in more complex thinking and became capable of abstract thought. According to Piaget, this is a part of the formal operational stage, which starts around 11 years of age and continues into adulthood. Adolescents in this stage can think logically about both concrete events and hypothetical situations, demonstrating an ability to use abstract thinking to solve problems, consider alternate solutions, and test potential outcomes. They are also known for the ability to debate ideas and opinions on topics like politics, religion, and justice, and for sometimes questioning authority or challenging established societal norms.